Recently, genes coding for useful, physiologically active peptides derived from eukaryotes, for example, .beta.-IFN have been cloned and linked to promoters derived from microorganisms to efficiently produce the desired physiologically active peptides in microorganisms by utilizing rapidly developed genetic engineering techniques [T. Taniguchi, et al.: Proc. Jap. J. Acad. sec B 55, 464-469 (1979), Japanese Published Unexamined Patent Application No. 77654/82, Japanese Published Unexamined Patent Application No. 110600/83].